The present invention relates to an electric machine for a motor vehicle. The electric machine has a rotor and a stator. For driving the rotor, the has a coil device for generating a rotary field. At least one winding overhang of the coil device protrudes from a flux-guiding device of the stator, i.e., for example the laminated core, into an environment of the stator. The invention also includes a motor vehicle with the electric machine.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
In an electric machine a torque is generated by the stator by means of a magnetic rotary field and is applied to the rotor. For generating the rotary field, individual electric coils of a coil device are alternately impinged with an electric current. Switching of the currents can be accomplished by an inverter. During the switching, switching edges occur in the form of high-frequency AC current signals and/or AC voltage signals, i.e., generally in the form of electrical disturbances in the electric machine.
A particular problem encountered in a motor vehicle is that the electric machine is surrounded by a plurality of electrically conducting components into which the electrical disturbances can be transmitted, for example via capacitive coupling. In particular in hybrid vehicles and battery driven electric vehicles (BEV—battery electric vehicle—electric car) it was found that due to the high-voltage supply voltage of more than 60 Volt and/or due to the drive currents for the electric drive motor of more than 10 ampere, in particular more than 50 ampere, the electrical disturbances are of a magnitude so as to be emitted as electromagnetic interference radiation after being transmitted by the components, and as a result may for example interfere with radio reception in the motor vehicle.
In other words in such a case the electromagnetic compatibility (EMV or EMC electromagnetic compatibility) is no longer ensured.
The measures known from the state of the art do not allow reducing an electrical disturbance originating from the electric machine, i.e., an electric field of interference or electromagnetic radiation, without adversely affecting the efficiency of the electric machine.
It would therefore be desirable and advantageous to provide an EMC measure for a motor vehicle by which introduction of electrical disturbances into the motor vehicle can be reduced below a predeterminable threshold value